1. Field of the Invention
The invention relates to a recording and/or playback apparatus for a magnetic tape which cooperates with at least one scanning element (hereinafter referred to as a tape recorder), and more particularly to a tape cassette recorder having a marking device for selectively applying index marks which identify the position of a magnetic head relative to the magnetic tape in at least one marking zone of a marking carrier. Such tape recorders have at least one marking element which is movable along the marking zone in synchronism with the relative movement between the magnetic tape and the head.
2. Description of the Prior Art
Such apparatus is for example described in U.S. Pat. No. 2,218,542 and is in particular intended for dictation purposes. The user of such apparatus can make optically identifiable marks in the form of punched-out slits in paper marking-carriers by using the marking elements of the marking device.
In addition, a number of other apparatus with marking devices and marking carriers are known, by means of which index marks are made in accordance with different methods, as by scribing on the marking carrier, by the removal of a layer of a special material from the marking carrier, by burning in a mark on a thermographic marking carrier, and the like, for example, see U.S. Pat. No. 2,898,112 and the published German Patent Application No. 1,224,526. All these devices are more or less intricate and expensive, demand a comparatively large amount of power for the application of the marks and produce marks on the marking carrier which cannot be erased, or are erasable only with great difficulty, so that a large number of interchangeable marking carriers must be supplied with such apparatus.
A carrier with magnetically alignable particles for the storage and visual read-out of information is also known from U.S. Pat. No. 3,683,382. This patent teaches that a visible image of a magnetic or electrostatic force field can be obtained by impressing the field on a continuous web or sheet of material having tiny liquid-containing chambers having field-alignable particles in the liquid, and gives examples of use of such a material for making visible graph lines on a strip chart recorder, x-y recorder or the like.